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		| Paper: | 
		Cosmological Reionization by the First Stars: Evolving Spectra of Population III | 
	 
	
		| Volume: | 
		267, Hot Star Workshop III: the Earliest Stages of Massive Star Birth | 
	 
	
		| Page: | 
		433 | 
	 
	
		| Authors: | 
		Tumlinson, J.; Shull, J. M.; Venkatesan, A. | 
	 
	
	
		| Abstract: | 
		The first stars have received attention as the leading candidates for the sources that reionized the IGM at redshifts z > 6. These stars are hotter and smaller than their counterparts of finite metallicity. We present recent results from an ongoing study of metal-free stars from a cosmological point of view. We have calculated evolving spectra of Pop III clusters. We find that ionizing radiation from these stars is substantially stronger and longer-lasting than that of Pop II stars, particularly in the HeII continuum (E > 4 Ryd). We use a semi-analytic reionization model to assess the effects of Pop III stars on the epochs of HI and HeII reionization. HeII recombination lines may provide a means of detecting metal-free stellar populations at high redshift. | 
	 
	
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